1. Field of the Invention
This invention relates generally to ultrasonic generators, transducers, and converters used for ultrasonic cleaning applications, and relates more particularly to an ultrasonic transducer or converter having a two-piece head mass adhesively bonded to a quartz or ceramic cleaning tank.
2. Description of the Relevant Art
Ultrasonic power at a predetermined frequency or range of frequencies is used to provide energy in a container or tank to ultrasonically clean, rinse, or otherwise process parts in an aqueous solution. Early ultrasonic cleaning systems consisted of transducers and tanks made primarily from stainless steel. U.S. Pat. Nos. 5,748,566 and 5,998,908 (incorporated herein by reference) relate to my development of a transducer made in part from Advanced Ceramic materials. It was recognized that a ceramic resonator within the transducer could provide significant improvements in performance. It was also recognized that tanks made from inert materials such as quartz and silicon carbide have advantages over stainless steel tanks, as disclosed in my co-pending application Ser. No. 10/840,919, filed May 7, 2004 (incorporated herein by reference).
Prior attempts have been made to bond or otherwise attach ultrasonic transducers to a quartz or silicon carbide cleaning tank, but were unsuccessful due to bond failures. If the material of the tank and that of the head mass of the ultrasonic transducer are different, there may be a mismatch in the coefficients of thermal expansion, which can cause failure of the adhesive bond. The tank may be made of quartz and the head mass of the transducer may be made of aluminum, which have significantly different coefficients of thermal expansion.